Reliability Assessment of Ship Longitudinal Strength for the Rational Ship Structural Design

J. Ocean Eng. Technol. 1998;12(4):8-15.

Oi-Hyun Kim;Jeong-Je Kim;

합리적인 선박구조설계를 위한 선체종강도의 신뢰성해석

김외현;김정제;

현대중공업 선박해양연구소;울산대학교 수송시스템공학부

Keywords: Ship structural design, ship longitudinnal strength, Relabilty analysis, Design variables, Ultimate strength, Target reliability index, Partial safety factor

핵심용어: 선박구조설계, 선체종강도, 신뢰성해석, 설계변수, 최종강도, 목표신뢰도지수, 부분안전계수

Abstract

"The application of the reliability analysis is investigated as a probabilistic approach for the rational ship structural design and for the development of a design format for ship longitudinal strength. The investigation into the probabilistic characteristics of design variables and the studies on the ultimate strength of ship’s hull girder are accomplished. Reliability analyses are carried out for 34 ships of tankers and bulk Carriers built in domestic shipyard considering some typical failure modes such as tensile yielding, ultimate strength of stiffened panel and ultimate strength of hull girder. The safety assessment of each ship and the derivation of target reliability index are performed. Reliability indices with respect to ship type and ship size are discussed. As results, some deviation of reliability indices among ships was observed for all failure modes. To provide more uniform levels of safety, a new strength criteria using partial safety factors is derived. Finally, a design format using partial safety factors has been proposed and this new design format gives consistent reliability indices which are close to the target value. "